Custom post type taxonomy exclude

Hi, I have a cutom post type named : art & design and i have a taxonomy called main slider, in one loop i have only posts from the taxonomy main slider and in the other loop i have the loop for the custom post type art & design but i want to exclude the taxonomy ?

1st loop

<?php
  	$args = array( 'artdesign_mainslider' => 'art-design-featured-post', 'posts_per_page' => 5 );
$loop = new WP_Query( $args );
while ( $loop->have_posts() ) : $loop->the_post();  ?>

<?php endwhile; ?>

2nd loop ( i want to exclude artdesign_mainslider)

<?php
    $args = array( 'post_type' => 'art_design', 'posts_per_page' => 10, );
$loop = new WP_Query( $args );
while ( $loop->have_posts() ) : $loop->the_post();  ?>

<?php endwhile; ?>